Extant literature shows that personality, appraisals and coping comprise a model that explains a significant proportion of the variance in distress in patients with breast cancer and their partners. However, much of the variance remains unexplained. Literature that examines patients and partners together shows that the distress and coping of one influence the distress and coping of the other, although we have yet to understand through which mechanisms. The proposed research is expected to identify variables that affect distress in patients and partners and explain how one spouse impacts the other. In the proposed study, we will determine the extent to which the variables from a cognitive stress model modified to include a dyadic component improve the model's predictive ability over the traditional model that does not include dyadic/spouse variables. We will determine this for both for patients and for their partners in an effort to better understand how a diagnosis of breast cancer leads to potentially long-standing psychological distress in couples. In order to reach these goals, 60 married or partnered women, diagnosed with breast cancer and undergoing adjuvant chemotherapy treatment, and their partners will be recruited. They will be sent an assessment battery through mail. Primary appraisals of the breast cancer, optimism, coping strategies (problem-focused coping, emotion-focused coping, relationship-focused coping, and emotional expression and processing coping) and distress (Profile of Mood States) will be assessed. The Actor Partner Interdependence Model using multilevel modeling with SAS PROC MIXED will be used to determine relationships among groups of variables from the model after controlling for any necessary demographic and disease variables. We expect that including partner variables in our analyses will result in more statistically significant variance predicted in distress than including only the individual's variables. Findings from the proposed study will inform clinical practice and also a larger, longitudinal study to determine variables important for interventions to reduce psychological morbidity for patients and partners throughout the cancer experience. [unreadable] [unreadable] [unreadable]